| Project/Area Number |
09490001
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
広領域
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| Research Institution | TOHOKU UNIVERSITY |
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Principal Investigator |
NIHEI Yoshiaki Fac. of Arts and Letters, Tohoku Univ., Prof., 文学部, 教授 (10007833)
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| Co-Investigator(Kenkyū-buntansha) |
HATAYAMA Toshiteru Fac. of Arts and Letters, Tohoku Univ., Prof., 文学部, 教授 (90048801)
HIGUCHI Hiroyoshi Graduate School of Agriculture and Life Sciences, Univ. of Tokyo, Prof., 大学院・農学生命科学研究科, 教授 (10111486)
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| Project Period (FY) |
1997 – 1999
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| Project Status |
Completed (Fiscal Year 1999)
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| Budget Amount *help |
¥4,100,000 (Direct Cost: ¥4,100,000)
Fiscal Year 1999: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1998: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 1997: ¥2,400,000 (Direct Cost: ¥2,400,000)
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| Keywords | Carrion Crows (Corvus corone) / Automobile-using behavior / Walnuts / Learning / Propagation / Walnut-dropping behavior / 道具利用 / 道具使用 |
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| Research Abstract |
In Sendai, Japan, Carrion crows Corvus corone have frequently been observed to use automobiles as nutcrackers. Crows put walnuts in front of the wheels of automobiles to let the cars run over the nuts, and eat the fragments of the nuts. We investigated how Carrion crows learn the car-using behavior and propagate the behavior among them. The main findings were as follows:
1 Variations of the nut-cracking behavior were considered to base on a general behavioral schema which consists of several variables.
2 Our questionnaire survey showed when and where the crows learned car-using behavior in Sendai. The behavior originated at a driving school in Sendai in the 1970s and has been spreading from there to surrounding areas.
3 There was no significant difference in energy efficiency between car-using behavior and walnut-dropping behavior (Adachi et al., 1998).
4 Observational studies showed that the sites where crows use automobiles as nutcrackers have common conditions. Further experimental studies clarified why the conditions are necessary.
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